Vehicle suspension



B. LIEBOWITZ.

VEH|CLE SUSPENSION.

APPLICATION FILED APmznlsls. RENEWED APR. 17,1911.

1322,56. Patented uly 11, 1922.

5] mm ntoz 315 his @Hovnew VEEICLE SUSPENSION.

To all whom it may concern:

Be it known that I, BENJAMIN LIEBOWITZ, a citizen of the United States, residing at the city, county, andState of New York, have invented certain new and useful Improvements in Vehicle Suspensions, of which the following is aspecification.

My invention relates to suspensions of the character disclosed in my Patent No. 1,240,992, issued Sept. 25, 1917, in which resilient support of body on axle is obtained by means of angularly movable tension mem bers acting in conjunction with initially strained springs, the initial strain whereof is greater than the subsequent strains due to. normal relative displacements of bodyand axle.

The principal objects of this invention are, to improve the construction of the suspension so that it may be readily applied to the present types of motor trucks and automobiles, to provide tension members which are laterally stiff and torsionally flexible, and to reduce thefriction of the pivotal supports of the tension members.

To these ends, as well as to attain other objects not specifically stated, my invention consists in the constructionand arrangement of parts hereinafter described and particularly pointed out in the claims. In the accompanying drawings, Fig. 1 is a diagrammatic side view of a suspension embodying my invention in one form. Fig. 2 is a detail side view of one of the, tension members and its supporting pivots partly in section; Fig. 3 is a plan view of the same; Fig. 4- is a fragmentary side view of a modified construction; Fig. 5 is, 'a plan view thereof partly in section and, Figs. 6 and 7 are fragmentary detail views of another modification. i

vReferring to the drawings, 1 indicates a wheel; 2 an axle ;3 the frame and 4 the body of an automobile or motor truck, all of which parts may be of any ordinary or ap proved construction and require no further description.

Rigidly fastened, to the frame 3 is a channel 5, into the ends of which are secured spring-sectionsfi, 7 by means of clips fil, 52, 53 and 54. If desired, a continuous Specification of Letters Patent. "Pgttgntgd J ly 11, 1922 Application filed April 27,1916, Serial No. 193,837. Renewed April. 17, 1917. Serial No. 162,

springmay be used instead of'the divided spring structure, but I prefer to employ the lattenas it saves unnecessary length of spring material. p

.The spring 67, inan unstrained condition, would assume the shape indicated by the, dotted lines 6 -7, but in my suspension 1t 1s subjected to a large initial strain. bv be ng bent, as shown in Fig. 1, and held 111 such position by restraint of the tension members The application of large initial strainer tensionto-the spring, when it is sustaining no load, is an essential condition to the proper working of the suspension, as 1S fully described in my patent hereinabove referred to. r f

.The lefttension member comprises forked end pieces or forgings12 and 13 connected by a "flat, relatively wide and thin, metal strap 10,.and similarly the right tension member. consists of end'pieces 14: and 15 and a connecting strap 11. The strap -like formation of the portions 10 and 11 give the tension members torsional flexibility whlle retaining lateral stiifness. Such construction prevents side sway of the suspens1 on, -and.permits the axle to tilt, due to dlfferences in level of the wheels at the 0ppos1 te ends of the axle, without torsionally straining the spring. or frame.

A yoke or. member 16 is rigidlyfastened tothe axle. 'Iheinnerfends of the tension members are pivoted to the yoke, while their outer ends are pivoted to the spring. In operation of the suspension, relative movement of body and axle" produces angular movement of the tension members, and it is desirable, therefore, in order not to interfere unduly with. the flexibility of the suspension, that the tension members should work on their pivots with little frictional resistance. i

To that end I provide the structure with knife-edge or rocker pivots, as is best seen in Figs. 2 and 3. Rigidly fastened in the spring-eye 6 is a pin 8 provided with knifeedges, which bear onthe hardened bearingsurfaces 21, secured in the forks of the end piece 12 of the tension-member; The pivot at the opposite end ofthe tension member comprises a pin 17 which is fixed in the forks of the end piece 13 and is provided with a knife-edge, which works on a bearing block 19 of the yoke 16. The construction of the rocker pivots 9 and 18 of the right-hand tension member is similar to that of the pivots 8 and 17. In the drawings I have shown a different form of rocker pivot at each end of the tension members, but it will be understood that either form of construction "may be used at both ends if desired. Preferably, however, the construction shown in the left hand end of Fig. 2 should be used at both ends of the tension members, that is, the construction in which the rocker bear-' ing or seat is rigid with the tension member and the rocker pin rigid with the spring- "eye or axle yoke eye, as the case may be.

I I The reason for this is that thefor'ce of the tension members "should always be at right angles to the rocker seat at the point of contact in order to avoid slippage under large angular displacements.

The suspension shown in Fig.1 is suitable for both the front and rear axles "of a motor vehicle in any case where, uponapplication of a vertical force, the axle will move in a plane substantially perpendicular to I the body; Where, however-,due to the con straint of radius rods, this condition is de parted from, as in the case of the rear axle of a "chain driven car, the construction hereinabove described will preferably be modicates a yo'ke provided' at its lower end with two lknife-ed ged pivots 27 and 28 laced as close together as is prae'ticableso that as the yoke rocks they will deviate only slightly from their normal horizontalplane. The

knife edges of said pivots bear on the hard-- 7 ened' be-aring blocks 29, 30 of the end forgings 23 ,24of'the te'nsio'nfmembers i1 0 and 11. In this case these-1e is caused to move through the are 'A by constraint of the radius rods (not shown) such as are usually employed in chain driven cars. Th'at movemeat will cause the yoke 26 to rock and will maintain the pivots 27, 28 in a relatively fixed position horizontally. This prevents the s ringjfre'm being undul deflect d by reason at thehorizont'al comp nent of the eurvili-nearmetip'n of the exit. I

Another modifieatien for the same parpese is shown in Figs. 6 and 7 in which the yoke 37 is pivotally mounted on the pin 38 fixed to the link 36, which link depends from the axle 2. In this construction the horizontal component of the axle displacement is taken care of by a rocking motion of the link 36.

, lVhere the axle ispivotally connected to the radius rods, as in most chain driven cars, the yoke 26 or the link 36, as the case may be, will be rigidly fastened to the axle, but

otherwise it will hang loosely thereon.

' It is obvious that various modifications in the details of construction andar'ran'genlent of parts may be made within the spirit and scope of my invention. V r

By the term initial strain, as used in this speei-fi'cationand the annexed claims, I mean the strain to which the spring is subjected when the suspension is in no load position; that is the initial strain is the minimum strain to which the spring is subjected through the range of the suspension move- 'e'nt. j

What I claim is:

y l. In; a vehicle suspension, an initially strained spring attached to the frame, the initial strain whereof is large in comparison with fthefsubsequent strains due to normal relative displacements of body and axle,

a yokeattached t0 the axle, and a pair of tension members secured at their ends to the yoke and to the ends of the spring respectively by means of rocker pivots.

'2. In a vehicle suspension an initially strained leaf spring, the initial strain where of is greater than the maximum subsequent strains 'dueto "relative displacements of body and axle within the limit'of the spring de sign, and a pair of tension members pivotally connectingthe ends of the spring with the axle.

g 3. vehicle suspension an initially strained leaf spring fixed to the frame, the initiaLstrainbeinglarge in comparison with the subsequent strains due to normal relative displacements ofbody and axle, a member attachedto the axle, and a pairo'f tensijon memfb'erspivotally secured at their ends tothe axle member and'to the ends of the sprite pec i e y v 4. In a vehicle suspension the combination of an axle, a vehicle frame, a pair of leafjspri'ngs secured to said frame and extending downwardly on opposite sides of the axle, said springs being subjected to an initial strain which is greater than the maximum subsequent strains due to relative displacements of body and axle Within the l-inr its of the spring design, and a pair of tension members connecting the lower ends of said springs to the axle. I

' 5. In a vehicle suspension the combination of an initially strained spring, a yoke, and a pair of tension members pivotaniy secured at their ends to the yoke and to the ends of the spring respectively, the portion of each tension member, intermediate the pivots, being relatively Wide and thin whereby to secure lateral stiffness and torsional flexibility.

6. In a vehicle suspension the combination of an initially strained spring, a yoke,

and. a pair of tension members pivotally secured at their ends to the yoke and to the ends pf the spring respectively, the intermediate portion of each tension member comprising relatively thin flanges arranged to provide torsional flexibility and fiexural stiffness.

BENJANIIN LIEBOWITZ. 

